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Thoughts on the Space Elevator 622

Posted by ScuttleMonkey
from the no-such-thing-as-an-inefficient-government dept.
Keith Curtis writes to tell us that Glenn Reynolds, of Instapundit fame, has posted his thoughts on why NASA should be building a space elevator instead or their current plans. Keith has also posted his throughts from an engineer's perspective (although admittadly still not a rocket scientist). "The challenges are many, but it has been a viable option since carbon nanotubes, structures so strong that one the width of a human hair could lift a car, were invented. A space elevator could be between 10 and 2000 times cheaper than conventional technology and will force NASA to change just about everything they do. Hopefully one day that bureaucracy will wake up and realize it."
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Thoughts on the Space Elevator

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  • Musak (Score:5, Funny)

    by Anonymous Coward on Wednesday September 21, 2005 @07:08PM (#13617788)
    Yeah but who wants to listen to that god awful music?
    • Re:Musak (Score:5, Funny)

      by Crash McBang (551190) on Wednesday September 21, 2005 @07:21PM (#13617886)
      You get used to it after the first 5,000 floors...
    • Re:Musak (Score:5, Funny)

      by fermion (181285) on Wednesday September 21, 2005 @10:05PM (#13618816) Homepage Journal
      not to mention the movie and safety talk. I think Red Dwarf said it best

      Welcome to Xpress Lifts, descent to floor sixteen. You will be going down two thousand, five hundred and sixty-seven floors and, for a small extra charge, you can enjoy the in-lift movie 'Gone With the Wind'. If you look to your right and to your left, you will notice there are no exits. In the highly unlikely event of the lift having to make a crash-landing, death is certain. Under your seats you will find a cassette for recording your last-minute testament, and from above your head a bag will drop containing sedatives and cyanide capsules.

      I would think the biggest issue would be safety. Two shuttle breakups in 15 some odd years is bad enough, but what will be required when we really have the promised trip to space every week.

      • Re:Musak (Score:4, Insightful)

        by ThePromenader (878501) on Thursday September 22, 2005 @04:46AM (#13619961) Homepage Journal
        Your post is a funny : )

        But ah beg to diffah. To be honest I can't think of anything safer than an elevator for 'point-to-point' space travel. If we can make a hair-thin cable strong enough to lift a car, imagine what weight a thousand of those strung together - say in five separate cables (not unlike today's elevators) - can assure. The cable's heaviest load, though, would be itself, and that towards its centre where Earth's gravity and the cable's own extra-gravitational circumferential pull meet up. Not to mention the additional stress caused by the cable's movements around its earth-fixed tether. But I'm sure that it's more than managable. <br/><br/>

        Another plus would be the long-term costs - Once built a space elevator would cost its maintenance and the energy to get it up there - yes there are other costs but I'm sure you all get the picture. In fact, who says we have to get up there <i>quickly</i>? For humans to get up to that orbital satellite-maintenance station, sure, but what about the satellites themselves? These could use "slower" energy - and why not solar power - to take their sweet time getting up there. Things would speed up towards the top anyways. We already have freight elevators, don't we?
    • Didn't Max Payne tought you how to deal with Musak? Just shoot the damn speaker. Ok, making a hole in a capsule that's heading to space might not be such a good idea, so lets replace the gun with a screwdriver and wire cutter. Just don't cut the wrong wire, the one leading to certain live support systems for example.
  • Pixiedust (Score:4, Insightful)

    by prurientknave (820507) on Wednesday September 21, 2005 @07:10PM (#13617800)
    If magic pixie dust were invented it would be such a waste to spend all this money on conventional boosters. Come on NASA! Drop what's known to work and concentrate on the pixie dust formula.
    • Re:Pixiedust (Score:4, Informative)

      by Bryansix (761547) on Wednesday September 21, 2005 @07:24PM (#13617900) Homepage
      http://en.wikipedia.org/wiki/Pixie_dust [wikipedia.org]
      It already exists. Just not for what you are thinking about using it for. IBM owns the patent on Pixie Dust. Although I can't see that they care about it anymore now that they sold thier hard drive division.
    • Re:Pixiedust (Score:5, Insightful)

      by An Onerous Coward (222037) on Wednesday September 21, 2005 @07:32PM (#13617964) Homepage
      I once read an interesting article on cluster computing, which basically said that the fastest and cheapest way to solve any truly big computational problem was, "Wait a few years before buying the cluster." Given the rates at which prices for storage, processing, and networking were plummeting, a problem that would take eight years to solve today could be solvable in four years two years out, and in two years two years from now. So by putting it off for two years, you'd shave two years off the project.

      The current plan doesn't get us to the moon until 2018 anyways, and without a cheap way to keep things flowing between here and the moon, the chance of a sustained human presence is nil. So we could spend $100B building basically the same propulsion-based solutions we've always been building, or we could spend a much smaller sum on fundamental materials research.

      I don't see it as a gamble, because without a drastically cheaper way to get into space, we'll just retrace the journeys of the Apollo missions. Then the whole nation will kick back, pop open a beer, mutter "Yep, still got it," and wait to do it all over again in 2050.

      Count me in with the pixie dusters.
      • Re:Pixiedust (Score:5, Insightful)

        by Asterixian (806481) on Wednesday September 21, 2005 @08:11PM (#13618239)
        Given the rates at which prices for storage, processing, and networking were plummeting, a problem that would take eight years to solve today could be solvable in four years two years out, and in two years two years from now. So by putting it off for two years, you'd shave two years off the project.

        This may be true in the everyday world of cut-throat competition, but if we call this "optimal" and everybody does it, everybody waits two years, and nobody puts forth the effort to realize the gain in productivity. Leeching off of technology that hasn't been invented yet reaps the benefits of work paid for by whomever goes first. I call it a technologically-oriented game of chicken.

        Looking more closely at NASA's past projects, you will find that NASA takes precisely that role - the government puts up huge sums of money on an unproven technology, and the world reaps the benefits years (or decades) later. From the taxpayer's perspective, the only important criterion is whether the indirect reward will pay back the taxpayer for the up-front costs.
      • Re:Pixiedust (Score:5, Interesting)

        by BJZQ8 (644168) on Wednesday September 21, 2005 @09:00PM (#13618515) Homepage Journal
        I agree completely. We've done the moon thing, and have tons of cool rocks. Why do it again? What will that $100 billion do for us that hasn't been done before? It would be much better spent researching and developing something like a 36,000-km nanotube ribbon than going up and getting more rocks. Even if the ribbon proves unproduceable, we would be investing in basic research, and not simply lining the pockets of the US space industry, ie Boeing, Lockheed-Martin, etc. to do something that has been done before.
      • Re:Pixiedust (Score:3, Interesting)

        by TallDave (916610)
        There isn't even really that much basic materials work that needs to be done. They just need to get the composite percentage up (iirc) from around 10% to around 50%. I think the success of carbon nanotube companies and SpaceShipOne suggests the best way to do this is for NASA to offer large monetary rewards, perhaps in the range of $10 - $100M, for producing a workable cable and climber power source. My understanding is those two things are the major engineering hurdles right now. Currently there is a N
    • Re:Pixiedust (Score:5, Interesting)

      by AKAImBatman (238306) * <akaimbatman @ g m a i l . c om> on Wednesday September 21, 2005 @08:07PM (#13618213) Homepage Journal
      Parent is not a troll. He's trying to make a point. The Space Elevator is a untested and unproven technology. Like all unproven technologies, there are bound to be hidden costs, hidden delays, and hidden engineering problems.

      NASA is taking the correct approach. They are building something that they *know* works first. They can then work out the pixie dust^H^H space elevator next.
      • Re:Pixiedust (Score:4, Insightful)

        by nwbvt (768631) on Wednesday September 21, 2005 @09:29PM (#13618662)
        " NASA is taking the correct approach. They are building something that they *know* works first. They can then work out the pixie dust^H^H space elevator next."

        Why? Whats the hurry? Would it really be the end of the world if we didn't get back to the Moon by 2020? Is this a critical mission whose failure would jeopardize national security?

        No, its a 100 billion dollar PR stunt. The best argument you can make for it is that in the process we are developing new technologies and discovering new ideas, but in that case wouldn't it make more sense to go with the new untested but potentially revolutionary technology than what is effectively the same thing we used 36 years ago? Doesn't going with what you know works completely defeat the point?

  • by thedak (833551) on Wednesday September 21, 2005 @07:11PM (#13617810) Journal
    But, I don't remember ever hearing that we actually have the technology to produce enough carbon nanotube material to actually build a prototype device of some sort let alone a cable spanning to LEO. I realize it's 14 years away.. but there's no guarentee we will actually have the capacity by that time. As far as I'm concerned we're better off building what can actually be finished come 2020 let alone tested and on our way to the moon.. again..
    • by ArbitraryConstant (763964) on Wednesday September 21, 2005 @07:21PM (#13617881) Homepage
      "But, I don't remember ever hearing that we actually have the technology to produce enough carbon nanotube material to actually build a prototype device of some sort let alone a cable spanning to LEO."

      A space elevator must extend to geosynchronous orbit, 36000 km up.
  • I wonder how long it will take for one of these elevators to reach their destination. If the elevators are going to take a long time they need to be big enough to hold some food and other supplies. I'm sure they will be big enough to send up large equipment though...
  • Launch Loop (Score:5, Informative)

    by QuantumG (50515) <qg@biodome.org> on Wednesday September 21, 2005 @07:12PM (#13617817) Homepage Journal
    Sigh. Ya know, we could build a structure to space with todays (hell, 20+ year old) technology if we wanted. The Launch Loop [launchloop.com] concept was published 20 years ago and is viable today. It costs less than a space elevator is predicted to cost and, unlike the space elevator, can be built from the ground up instead of from orbit down. So yeah, please stop saying stuff like: once we have strong carbon nanotube fibres we'll have a space elevator two weeks later. It doesn't work like that. The majority of studies that remain to be done to make the Launch Loop a reality are much the same as the many studies that still need to be done to make the space elevator a reality. Someone has got to finance those studies and unless you can get PhD students to do it on government funding that means you've got to pour money into a hole that might never fill up.
    • I think everyone is too laxy to open those PDFs, so why do you explain what it is for us...
    • Re:Launch Loop (Score:5, Informative)

      by deathcloset (626704) on Wednesday September 21, 2005 @07:27PM (#13617929) Journal
      The launch loop still requires classic reentry for space vehicles.

      This is still a fantastic idea for getting things up, though.

      It's just getting back down that runs into the same old problems (and comming down from space gently is one of the best (most overlooked) features of a space elevator).

      Its nicer to repel than base-jump.
      • Re:Launch Loop (Score:4, Informative)

        by QuantumG (50515) <qg@biodome.org> on Wednesday September 21, 2005 @07:45PM (#13618067) Homepage Journal
        If you don't spend any fuel getting up there it's pretty easy to carry enough fuel to decelerate and re-enter the atmosphere. Heat shields are only necessary because we can't afford to launch surplus fuel to slow down.. we have to use the atmosphere to brake.
    • by GroeFaZ (850443) on Wednesday September 21, 2005 @07:35PM (#13617991)
      Launch Loop presentation [launchloop.com] and Space Elevator presentation [liftport.com] .

      For large projects to be realized, they either have to be of decisive strategic/military value during war (Manhattan project), or they have to completely capture the hearts of the citizens that are supposed to pay for it all (Apollo Project, "before this decade is out..."). Clearly, for the Space Elevator, the latter is the case. I, for one, have not heard of Launch Loop before, and the dry PDFs and text files that are Google's #1 on the term didn't really invite me to care about it. The Space Elevator, on the other hand, has been part of the popular culture for decades, and has recently surged astronomically (no pun intended) in terms of mainstream recognition.

      Just as it would have been more affordable and scientifically more valuable to gradually conquer space and ultimately the moon (i.e. with manned space stations and a launch from space etc.), it was the extreme appeal of the "moon shot", the giant leap that won the favor over the more economical approach.
  • private ventures (Score:3, Informative)

    by timmarhy (659436) on Wednesday September 21, 2005 @07:12PM (#13617819)
    this is where private ventures come in. let them take the risks and develope the tech. i'm dubious about space evelvators, but hell it's at least possible in theory if you can find materials that will last
  • Hmmm.... (Score:2, Interesting)

    by Chanc_Gorkon (94133)
    A space elevator will be made of carbon fiber nanotubes correct?? What would be the effect on a hurricane hitting the elevator? Can the string be realed in from one end?? Would it be more prudent to build this in a place far away from a coastline??
    • Re:Hmmm.... (Score:2, Interesting)

      by deanoaz (843940)
      >>> Would it be more prudent to build this in a place far away from a coastline??

      After reading "Red Mars" I don't think it will matter where you build it. If it comes down it will leave a path of destruction all the way around the Earth's circumference.

      Besides, the termination point needs to be easily accessible or you negate much of the advantage of having the elevator.
    • Re:Hmmm.... (Score:5, Informative)

      by king-manic (409855) on Wednesday September 21, 2005 @07:57PM (#13618137)
      A space elevator will be made of carbon fiber nanotubes correct?? What would be the effect on a hurricane hitting the elevator? Can the string be realed in from one end?? Would it be more prudent to build this in a place far away from a coastline??

      negliable if built correctly. The local winds wouldn't have enough kinetic force to move the cable much.
      • Re:Hmmm.... (Score:3, Insightful)

        by ebuck (585470)
        No, but I'll bet a 2x4 at 90 miles per hour will.

        Hurricanes aren't solely destructive because of the wind. A lot of that destructive power comes from the things the wind is carrying. At a minimum you have water, which makes the wind a bit dense. But in reality, you have all sorts of debris. Roof shingles, plants, etc.

        Carbon nano-tubes have great strenths, but most things under linear stretching don't require a lot of lateral impact to cause them to break.
    • Re:Hmmm.... (Score:3, Informative)

      by Phanatic1a (413374)
      Hurricanes aren't an issue.

      You would be building this very close to, if not on, the equator. Hurricanes do not form there, and I can't even think of one that has ever crossed the equator.
  • What about rescues? (Score:3, Interesting)

    by saskboy (600063) on Wednesday September 21, 2005 @07:13PM (#13617823) Homepage Journal
    Why isn't this stuff being used as an emergency rescue material, to make ladders that can be telescoped up to the 30th floor of skyscrapers? Surely there could be less ambitious projects for this material before committing to something that has to deal with the extreme stresses and temperatures in space and the upper atmosphere?

    Make a model of a space ladder/elevator, by designing something that can save lives here at home, and it will take off like a rocket in the public's eye, pardon the pun.

  • We're nowhere near ready to start manufacturing tubes suitable for use in an elevator cable. (Maybe you've noticed their lack of use elsewhere.)

    • Perhaps if more research was being done into their manufacture we would already have them elsewhere.

      But instead time and money is spent on revamping the Apollo capsule (nevertheless, a good revamp to be fair).
      • Re:nyet-o-tubes (Score:3, Insightful)

        by Jeff DeMaagd (2015)
        I don't think that's the right way to think of it. Call it stepping stones. There's no point in abandoning short term projects for a long term one. There's no point in completely abandoning known working tech for something that's totally theoretical.

        It's probably a lot cheaper to "revamp the Apollo capsule" than it is to insist on such a great leap in tech, that tech being more of a curiosity at the moment than anything else. Taking things too radically different is what got us the Space Shuttle, when
  • by millisa (151093) on Wednesday September 21, 2005 @07:14PM (#13617830)
    I like the idea of the space elevator . . . but won't it be a prime target for terrorist attacks? I mean, if I was a terrorist, it'd be the first place I'd direct my hijacked pla . . . moment, there's a knock at my door.
    • You know, if you start fearing, then you have to fear your own fears... as the Iron Maiden said:

      When the light begins to change
      I sometimes feel a little strange
      A little anxious when it's dark ...
      I have a constant fear that someone's always near ...
      I have a phobia that someone's allways there ...
      Sometimes when you're scared to take a look
      At the corner of the room
      You've sensed that something's watching you

      Have you ever been alone at night
      Thought you heard footsteps behind
      And turned around and no one's there?
    • that would be your neighbor. These days, terrorists and the feds do not bother knocking.
    • Re:Doom and gloom (Score:3, Insightful)

      by khallow (566160)
      Make a bunch of them. They're less attractive as targets if there are dozens or hundreds of them.
    • Re:Doom and gloom (Score:4, Insightful)

      by fbg111 (529550) on Thursday September 22, 2005 @03:48AM (#13619838)
      Terrorists aren't going to be crashing planes into buildings anymore. The only reason they got away with it the first time was b/c the passengers didn't know their plans, and the ones who did, on the flight that crashed in Pennsylvania, fought back. From now on, for any hijacking attempt, the passengers and crew will assume the intent is to crash the plane and fight back. Everyone knows the rules have changed and that cooperation and passivity = death.

      Tiny, successfully concealed bombs are more of a concern now than suicide hijackings, but those won't pose much of a threat to space elevators as long as official flight paths require staying away from them.
  • Oh yeah, let's spend our money on a space elevator. The world's longest carbon nanotubes are what, half a centimeter in length right now? That means only 62,000 miles - .5 cm to go!
  • by cetialphav (246516) on Wednesday September 21, 2005 @07:15PM (#13617841)
    The August issue of IEEE Spectrum also had a story about the space elevator. This article is available online here [ieee.org]. Not knowing much about the space elevator, I found this article very informative.
  • Burn up (Score:2, Informative)

    by geekoid (135745)
    People keep saying if it fell it would burn up, but it would seem to me that something strong enough to support all the weight needed would be strong enough to withstand any heat generated by falling.
    Considering that it wouldn't betravelling that fast, I don't see how it could generate a lot of heat. Compared to say a shuttle reentry.

    Wouldn't we also need to build it from space down?

    All this is mute until we can make nano tubes as easily and reliable as we make rope.
    • People keep saying if it fell it would burn up, but it would seem to me that something strong enough to support all the weight needed would be strong enough to withstand any heat generated by falling.
      Diamond is one of the hardest substances around... but see what you are left with when you throw one into a fire.
      • Except this isn't a fire.

        For example, the shuttle travels around the earth onces every 90 minutes, making it's speed about 12,000 miles per hour relative to a fixed point on earth.

        the counter weight is traveling at 0 mph compared to a stationary point on earth.

        it won't have enough speed behind it to generate much friction.

    • Re:Burn up (Score:2, Informative)

      by Xarius (691264)
      All this is mute until we can make nano tubes as easily and reliable as we make rope.

      So no-one is able to speak aloud about it?

      Ooooooh, you mean moot [reference.com]!

      </pedant>
  • 3? (Score:2, Insightful)

    by hunterx11 (778171)
    I can understand the occasional typo slipping through, but three? Come on; dupe or don't proofread, but don't do both.
  • What would you recommend for space elevator musac?

    It's going to be one hell of a long ride and I'd hate to overdose on strings.

  • Yes and No (Score:5, Interesting)

    by JaredOfEuropa (526365) on Wednesday September 21, 2005 @07:16PM (#13617854) Journal
    The space elevator seems to be still hovering at that point where it certainly looks to be theoretically feasible, but where no one really has a clear path towards bringing this construct about in reality. (Or is it that there are still a few people laughing at the idea, if you know what I mean?). It seems to me that it would be foolish for NASA to abandon its current plans in favour of this unproven idea, yet it might be wise to throw some money and effort at it.
    It would cost about $6 billion in today's dollars just to complete the structure itself, according to my study
    I've heard a similar figure before, and it's amazingly cheap if you think about it. We, as a silly small country, have blown close to this amount on a couple of utterly useless railroad lines. If we could have had a working space elevator instead...
    • Re:Yes and No (Score:4, Insightful)

      by zippthorne (748122) on Wednesday September 21, 2005 @07:54PM (#13618122) Journal
      Well we still need relatively cheap heavy launch vehicles to build the space elevator in the first place, so I don't see working on an apollo type project as being an incompatable goal.
    • Re:Yes and No (Score:3, Informative)

      by roystgnr (4015)
      The space elevator seems to be still hovering at that point where it certainly looks to be theoretically feasible, but where no one really has a clear path towards bringing this construct about in reality.

      New rockets are engineering work: we have all the materials we need to use, we know all the physics that describes their behavior, and so as you said there's a clear (albeit expensive) path to figuring out how to put it all together.

      A space elevator would still require science work, because the central pro
  • by HermanAB (661181) on Wednesday September 21, 2005 @07:17PM (#13617856)
    First of all, the ribbon idea won't work, it will get curled up since it will stretch unevenly and wind and dirt will do the rest. The only practical shape for a rope is a round one. Secondly, building a climber with motors and lasers and crap is totally ridiculous, unbalanced and inefficient. Put a friggen pully at the counterweight, with solar panels and an electric motor and another damn pully at the bottom with another motor, then run two cars up and down. Then the system is balanced. Yes, the two cars will probably bang against each other when passing - so slow down when halfway and shape them to handle it so they won't get stuck even if the ropes are twisted. KISS.
    • Counterweights won't work. As a car approaches the upper station, its weight diminishes to zero.
      • The force in a rope is always tension and always the same everywhere along its length (assuming zero mass). You can't push a rope.

        Therefore, a system with two cars and pulleys will always be almost in balance. The actual force in the rope will change depending on where exactly the cars are, due to centripetal forces.

        The 'almost' is due to taking up more stuff than you are bringing down, or the other way round if you are mining a solid naquata asteroid, or due to a load of gold plated latinum as payment fro
    • Further, the ribbon has to taper to allow the thing to not break, so the pulley idea is unworkable.
  • Money (Score:3, Insightful)

    by imunfair (877689) on Wednesday September 21, 2005 @07:17PM (#13617863) Homepage
    I know we have to plan for the future and all, but since Mars travel probably won't be viable or even valuable for another 60 to 80 years (by which time I'll probably be dead) I would much rather have a nice reduction in taxes.

    How about this - reduce our taxes a bit, and for the non-critical portion of our taxes let us choose what program they go toward funding. Some people might choose a government funded AIDS cure - some might choose Mars exploration ... but I really think the people should be allowed to choose which optional programs get their money - if it really needs to be taken from them in the first place.
  • I dont get it... (Score:4, Insightful)

    by imsabbel (611519) on Wednesday September 21, 2005 @07:19PM (#13617872)
    Maybe i am a bit out of touch (although i doubt it, being physicist and seeing people who actively work in the nanoparticle research and astrophysics department everyday), but i think this is all such a bullshit.

    Space elevator this, space elevator that. Its just a pie-in-the-sky dream, and will be for the next century(ies). We dont have bucktubes "thick as a hair but strong enough to lift a car".
    We dont even have them a meter long and strong enough to lift an apple.
    And even than, it took millenia to get from iron->steel->a few km steel wire for bridges/ect.
    Singularity this or that, you shouldnt expect something like the support of the golden gate bridge via nanotube based cables the next decade(s)
    (not even mentioning the hurdles of a structure 30.000km+ long and sturdy enough to support the lifting vehicle and atmospheric conditions).

    Also, the best we ever did concerning long wires and space was a test a few years ago, where they even failed to unwind a 300km, unstained wire in free space.

    Not to mention that to get the whole framework running you need an efficent way of getting material and people up there to begin with... without a shuttle mk2 or 3 or 4 or 5 there is not even a point to start the whole shit.

    But it seems nowaydays you only need to throw some buzzwords like "nanotubes" into the crowed and they would believe you even if you promised them portable teleporters...
    • by cephyn (461066) on Wednesday September 21, 2005 @07:35PM (#13617987) Homepage
      You make a good point. nanotube based teleporters would be faster and more cost-effective than a space elevator!

      I say we put $12bn or so into nanotube powered teleporters. who's with me!?
    • by deathcloset (626704) on Wednesday September 21, 2005 @07:58PM (#13618144) Journal
      you're a physicist?

      how could you use an analogy like "it took millenia to get from iron->steel->a few dm steel wire for bridges" when it took millenia to get from horse and carriage to the car...but then only a half-century to get into space?

      seriously, what's the average velocity of a horse and carriage vs. the average speed of an orbiting body?

      now juxtapose that over that timeline...

      and what about energy? we had fire to heat us for millenia. then within decades of the light-bulb we have nuclear reactors.

      please formulate a similar chart to the aforementioned.

      your the kind of physicist who looks through microscopes not telescopes, aren't you?
      • Re:I dont get it... (Score:4, Interesting)

        by Goldsmith (561202) on Thursday September 22, 2005 @03:07AM (#13619743)
        I am a physicist who works in nanotechnology, carbon nanotubes even. I guess I would be one of those physicists who looks through a microscope, and not a telescope. I'm really not sure if you were trying to make a point with that line, but it seems a funny thing to say in a discussion about nanotechnology.

        The things which are coming will blow your mind, but a space elevator with nanotubes isn't happening any time soon, despite what any historians may tell you. Contrary to what the "article" suggests, NASA IS working on this technology. They have spent a huge amount of money trying to get someone to grow a rope of continuous nanotubes just 1 meter long. Some of the best people in the world at nanotube growth are working on this (and have been working on this), and it will take a few years yet before they actually do it. Consider that two nanotubes tied (welded, bound, woven...) together are nowhere near as strong as one continuous nanotube. Consider also that nanotubes grow at around 10^-5 meters/s. Geosynchronous orbit is about 3.6*10^7 meters away. Here, really is the fundamental problem if we're going to try to grow a space elevator. If you go through the math, it would take about 10^5 years with today's technology, which makes the prediction of centuries very optimistic. I think it will take less than centuries (as in, I think we will find new growth or welding techniques), but there may be better ways of getting into space.
  • "an engineer's perspective (although admittadly still not a rocket scientist)"

    That's even better, because this is an engineering project, not rocketry.

    The first thing that I thought of when I first heard about this is what a great terrorist target it would make. You could shoot at it for many miles around, which might not affect it much if it's as strong as it sounds like the material is, but one would be able to see when it was in use. It's unrealistic to think that people around the world would cons

  • by Tackhead (54550) on Wednesday September 21, 2005 @07:22PM (#13617890)
    > The challenges are many, but it has been a viable option since carbon nanotubes, structures so strong that one the width of a human hair could lift a car, were invented.

    No, it hasn't.

    The space elevator will become viable when someone creates a strand of carbon nanotube and lifts a car with it.

    If you want to make me believe that a carbon nanotube space elevator is a viable proposition, demostrate that you can build a carbon nanotube suspension bridge first.

    Doesn't have to be a replacement for the Brooklyn Bridge or the Golden Gate. A footpath over a creek at your local engineering college will do.

    Until then, you're as likely to go into orbit on a space elevator's as you are on a matter/antimatter drive: as in "not at all".

  • A matter of time (Score:5, Informative)

    by lightyear4 (852813) on Wednesday September 21, 2005 @07:23PM (#13617896) Homepage
    The LiftPort Group of companies working towards a space-elevator are making a great deal of progress. Slashdot reported on the faa approval [slashdot.org] of their high altitude tests, for example. See here [liftport.com] and here [liftport.com] for more LiftPort specific information. Check here [www.isr.us] and here here [www.isr.us] for several reports concerning the viability of the elevator -- be sure to check the NIAC pdf. Blaise Gassend has a great collection of information [mit.edu]. Finally, though carbon nanotubes are still in their infancy (its been a little around ten years since they were discovered) - their theoretical tensile strengths are perfect for application in a space elevator construction. This recent development [anl.gov] spells a rosy future, and many innovations yet to come.
    • by dbIII (701233)

      The LiftPort Group of companies working towards a space-elevator

      I live in a place where a former leader was taken in by a cure for cancer, a fake hydrogen car that generated it's own fuel from water, a commercial space launching site that was going to be set up by a two person company and various other scams. Is LiftPort promising a return in the next decade when not even the basic material exists and is thus a snakeoil scam - or is it a serious research group taking the very long view and letting all pot

  • The proposal to take 12 years to replicate what we achieved ofer 35 years ago in only 9 years is ridiculous and excessively priced. The problem is that the engineering talent isn't at NASA anymore, they cant look beyond doing the same design that has been done over and over since von Braun, and the whole setup is just a welfare program for bloated aerospace conglomorates.

    On the otherhand, the study that purported to show that a space elevator could be built for a few billion dollars is sheer fanasy. Single
  • Did you know that elevators smell different to midgets?

    This should hold true for space elevators as well.
  • by Chysn (898420) on Wednesday September 21, 2005 @07:29PM (#13617938)
    ...one giant leap for the first wise ass to press all the buttons (Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere...) and piss off the other astronauts.
  • KE = 0.5 * m * v^2 (Score:5, Insightful)

    by klossner (733867) on Wednesday September 21, 2005 @07:36PM (#13618005)
    Structural engineering issues aside, the big problem with space elevators is the junk in low earth orbit. If a 200 kg object hits the structure at a relative velocity of 15,000 MPH, it will release energy equivalent to one ton of TNT.
  • by alizard (107678) <alizard@noSpAM.ecis.com> on Wednesday September 21, 2005 @07:51PM (#13618102) Homepage
    Show me an actual, working 100 meter long CNT cable with strengths comparable to what the Space Elevator will require and I'm ready to discuss it.

    If you simply want to get cheap payload into orbit this decade using materials that are NOT theoretical, find a way to get funding to the blimp-to-orbit people at JP Aerospace [jpaerospace.com].

    Lots of things wrong with the Space Elevator concept... it breaking could kill a lot of people... but the dealkiller is that you can't build a structure with theoretical materials, and it shouldn't take a "rocket scientist" to figure this out.

  • by everphilski (877346) on Wednesday September 21, 2005 @07:52PM (#13618111) Journal
    Can be... could be... That's the problem. The tech isn't there. The carbon nanotubes that are long enough, aren't strong enough. The carbon nanotubes that are strong enough aren't nearly long enough.

    The tech isn't there. How can they start building something that doesn't have the prerequisite materials? The current plan NASA is proposing they can start building **soon**.

    The R&D you need to produce space elevators is currently being performed worldwide by a variety of companies and is well-funded. Diverting $100B isn't going to up the timescale **that** much. Not to mention while it looks good on paper, we haven't even tried a prototype yet.

    -everphilski-
  • by patternjuggler (738978) on Wednesday September 21, 2005 @09:05PM (#13618541) Homepage
    I think we need billions of dollars of investment in upgrading our antimatter production facilities. The space elevator only gets you into orbit, antimatter [psu.edu] can get you to nearby stars.

Computers are unreliable, but humans are even more unreliable. Any system which depends on human reliability is unreliable. -- Gilb

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